Add example for 'Evening' time of day in Get-Greeting documentation (#13)

This pull request adds an additional example to the documentation for
the `Get-Greeting` function, demonstrating usage with the 'Evening' time
of day. No code logic was changed—only the documentation was updated for
clarity.

Author: MariusStorhaug

src/functions/public/Get-Greeting.ps1

@@ -9,7 +9,12 @@
         .EXAMPLE
         Get-Greeting -TimeOfDay 'Morning'
 
-        Returns "Good Morning!"
+        Returns "Good Morning!" to the user.
+
+        .EXAMPLE
+        Get-Greeting -TimeOfDay 'Evening'
+
+        Returns "Good Evening!" to the user.
 
         .LINK
         https://MariusStorhaug.github.io/MariusTestModule/Functions/Get-Greeting/